Curved ultrasonic blade having a trapezoidal cross section

A balanced ultrasonic surgical instrument including a curved ultrasonic surgical blade, wherein said ultrasonic surgical instrument comprises;

• an ultrasonic transmission rod having a proximal end and a distal end;
• a balance region including first and second balance asymmetries wherein said balance region extends from a node point at said distal end of said ultrasonic transmission rod to a proximal end of said curved ultrasonic surgical blade, wherein said curved ultrasonic surgical blade comprises;
• a distal end;
• a proximal end connected to said balance region;
• a concave top surface including a central ridge;
• a convex bottom surface wherein said convex bottom surface has a width greater than twice the width of said central ridge;
• and
• first and second side walls connecting said convex bottom surface to said central ridge, wherein said first and second side walls form a portion of said concave top surface such that said curved ultrasonic surgical blade has a substantially trapezoidal cross-section.